Underwear Bomber Renews Calls for ‘Naked Scanners’

After an alleged terrorist unsuccessfully tried to detonate his explosive underwear on a Christmas Day flight to Detroit, current and former American officials are now using the failed attack to push for more airport scanners to spot such explosives — and a lot more.

The Transportation Security Administration in recent years has tried out a series of “whole-body imagers” to look for threats that typical metal detectors can’t find. These systems are the only way that smuggled explosives, like the one officials say was brought on the Christmas flight, can be reliably found.

“You’ve got to find some way of detecting things in parts of the body that aren’t easy to get at,” former Homeland Security chief Michael Chertoff told The Washington Post. “It’s either pat-downs or imaging.”

TSA has worked with two basic technologies to upgrade its passenger screening systems. Millimeter-wave sensors emit radio frequencies, and measure the differences in radiated energy. The result is a detailed, 3-D image of the passenger that looks sort of like a photo negative.

Similarly, backscatter x-ray scanners send out low-intensity beams, and watch how the x-ray photons get reflected back. (Old-school machines simply sent the x-ray through the object.) “Elements with lower atomic numbers (fewer protons) on the periodic table scatter X-ray photons very powerfully, while elements located farther down on the periodic table tend to absorb more photons than they scatter.

Most organics are located closer to the start of the periodic table. So backscatter systems are very good at imaging organic material — much better than dual-energy systems.

But it’s unclear how far the TSA will be allowed to go in deploying these systems. Because the same technology that allows the scanners to find explosive underwear can also provide some rather revealing glimpses of passengers’ bodies.

The agency says there’s no privacy problem. “Facial features” (and, presumably, other body parts) “are blurred when our officers see the images,” the TSA insists. Nor will the agency “keep, store or transmit images. Once deleted, they are gone forever…. For additional privacy, the officer viewing the image is in a separate room and will never see the passenger, and the officer attending to the passenger will never see the image.”

But privacy groups aren’t exactly comforted by the agency’s assurances. TSA has already reversed earlier stands on the scanners, the groups say.

The Electronic Privacy Information Center filed a lawsuit against the Department of Homeland Security on Nov. 9, to force it to give up information about the scanners. “TSA has stated that whole-body imaging would not be mandatory for passengers,” the Center noted in its complaint. “On Feb.18, 2009, TSA announced that it would require passengers at six airports to submit to whole-body imaging in place of the standard metal detector search, which contravenes its earlier statement.”

“Yes, there is some brief violation of privacy with a full-body scan,” Rep. Peter King, the top Republican on the House Homeland Security Committee, told Face the Nation. “But on the other hand, if we can save thousands of lives, to me, we have to make that decision, and we have to come down on the side of saving thousands of lives.”

But that logic makes about as much sense as the TSA’s new rules forcing passengers to stay in their seats for the last hour of a flight, says security guru Bruce Schneier. “It’s the same magical thinking we’re used to getting from the TSA,” he tells Danger Room. “Descend on what the terrorists happened to do last time, and we’ll all be safe. As if they won’t think of something else.”